Conventional footwear are generally provided with an insole positioned on the upper surface of the sole of the footwear. The insole is generally affixed to the upper surface of the sole of the footwear and provide a protective layer of material between the foot of the user and the upper surface of the sole of the footwear.
Conventionally, the insoles used in the footwear are formed of a surface lining and a harder and more rigid lining below the surface lining. The surface lining is generally adhesively secured to the more rigid lining, and the combination layer of the surface lining and the rigid lining is secured to the upper surface of the sole of the footwear by adhesives, sewing, nailing, or other conventional methods of attaching the insole to the surface of the sole of the footwear.
Conventional footwear construction incorporating insoles, as described above, fail to provide both sufficient cushioning and adequate flexibility. More specifically, because the insoles are constructed to primarily provide separation and a protective layer between a wearer's foot and the upper sole of the footwear device, the insoles are generally constructed with very little or no cushioning, and further, due to the rigidity of the materials that form the insole layer, flexibility is limited.
Furthermore, in a ball-to-ball, or ¾ welt, footwear construction, in particular, conventional insoles fail to provide cushioning to comfortably support the entire plantar surface of a human foot. More specifically, in the construction of ball-to-ball footwear, a shank portion, or the region of the footwear and the corresponding region of the insole forward of the heel area and rearward of the forefoot area, is narrowed in comparison to a full welt footwear construction. According to such construction, the insole is stitched to an outsole of the footwear from an area corresponding to a ball area of a foot at a medial side of the footwear, to an area corresponding to a ball area of the foot at a lateral side of the footwear, around the periphery of the outsole of the footwear. It is also customary to secure the shank portion of the insole on the inner surface of the sole of the footwear by using holding members, for example, nails or staples, which are generally driven upwardly from the outer sole of the footwear.
Due to the previously described construction, it is necessary for the insole to be formed of a material that is capable of retaining the holding member. Thus, materials that are rigid and which resist flexibility are used to retain the holding members. According to such construction, however, cushioning is omitted from the footwear in order to provide a layer that can retain the holding members. As a result, such footwear construction fails to provide sufficient cushion and comfort to a user.
Accordingly, conventional insoles have been unable to meet both the construction requirements and the comfort requirements necessary to provide both a sturdy construction as well as adequate comfort for a wearer. Thus, there exists a need for an insole that is capable of providing both comfort and flexibility.